Piston-inserting device



A. E. WATTS. PISTON INSERTING DEVICE.

APPLICATION FILED FEB. 6. 1920.

1,375,744. Patented Apr- 26, 1921.

lapping.

UNITED STATES FFlQE.

PISTON-INSERTING DEVICE.

Specification of Letters Patent.

Patented Apr. 25, 1921.

Application filed February 6, 1920. Serial No. 856,726.

exact description.

This invention relates to improvements in devices for inserting the pistons of internal combustion engines and the like, and the object of the invention is to provide means for contracting the rings of a pistonto the diameter of the cylinder and holding them in such contracted position until they are.

introduced into the cylinder.

A further object is to provide a device which may be very quickly and easily operated to contract all the rings of a piston simultaneously.

A still further objectis to provide a device which may be adjusted to a variety of v difi erently sized pistons.

. The device consists briefly of a strip or sheet of thin flexible material adapted to be wrapped around a piston to form a surrounding sleeve which can then be contracted by a suitable means until it fits tightly around the piston and compresses the rings to the diameter of the cylinder. The sleeve when alined with a cylinder will hold the rings in compression, so that the piston and its rings may be quickly and easily forced from the sleeve into the cylinder.

In the drawings which illustrate the invention Figure l is a plan view of the device open and ready to receive a piston.

Fig. 2 is a plan view of clamped around a piston.

Fig. 8 is an elevation of the device.

l-is a perspective view of a slightly modified form of operating lever.

Fig. 5 is a perspective view of an alternative form of adjusting device.

Referring more particularly to the drawings, 11 designates a sheet or strip of thin flexible material, such as spring tempered steel. The sheet is bent roughly to cylindrical form with its ends 12 and 13 over- The inner end 12 is provided at the upper and lower edges with lugs 14,

the device as 'which are bent outwardly over the sheet adjacent the end 13 and serve to hold the sheet ends in alinement, and together, so

that a roughly cylindrical sleeve results. The end 13 is looped on itself as at 15 to form the socket of a hinge, the loop being comparatively large so as to carry the axis thereof some distance outside the sleeve. One edge of the strip which forms what is regarded as the bottom of the sleeve is provided with a plurality of outward projections 16 which form feet adapted to rest on the top of an engine cylinder and support the sleeve. This completes the sleeve proper.

The sleeve contracting means includes a lever, a pawl fixed to the sleeveanda re silient connection between the two. A. U- shaped lever 17 having its arms curved to approximately the curvature of the sleeve is pivoted at the extremities of its arms to the sleeve end 13 by a pin 18 passing through the looplo. The sheet 11 is provided on the outer surface of the sleeve toward the end 13 with a pair of small brackets 19 which are located on the opposite side of the lugs 14 from the loop 15. A suitably formed pawl 20 having one or more teeth 21 is pivotally mounted between these brackets axially parallel with the sleeve. This pawl may be provided with a tail 22 for convenience or operation and is normally actuated by a spring 23, which presses the teeth 20 against the outer surface of the sleeve. A pair 01" helical springs 2d are connected one tooach arm or" the lever by a stud 25 located somedistance from the hinge pin 18 of the lever. These springs are connect ed at their opposite ends to flexible adjusting members 26, which are engaged and held by the teeth 21 of the pawl. Theseadjusting members may be of any suitable form but are preferably fiat link chains as shown. In order to uniformly and quickly adjust both chains, the free ends of same may be connected by a bar 27. As will be clearly seen in Figs. 1 and 2, the lever and pawl are attached to he same end of the strip 11 forming the sleeve and the springs and adjusting members 26 pass around the sleeve betweenthe lever and pawl and so encircle the sleeve and inclose the free end 12 of the sheet 11. Obviously, a contraction of this encircling means will cause contraction of the sleeve. Owing to the large size of the'hinge pin 15 which carries the pivotal' center well outside the sleeve, the line of tension between the springs 24 and studs 25 will lie well insidethis center or axis,

so that when the lever lies against the sleeve, as shown in 2, the tension of the springs will operate to hold the lever against the sleeve. Any suitable number of guide loops 28 may be attached to the outer surface of the sleeve to hold the springs 24 and ad justing means 26 in proper position' In Fig. 1, a slight modification is illus trated in which the arms of the lever 11 are slotted as at 29, one end of each slot being substantially in the location of the stud 26 and the slot extending toward the free end of the lever. With a lever of this form the spring attaching studs 25 are connected by abar 30 parallel with the pin 18 and adapted to slide in the slots 29 toward or away from the pin 18, so as to provide for greater elongation of the sleeve encircling means in the open position of the device shown in Fig. 1, by permitting the points of spring attachment of the lever to move out to the free end of the lever.

The alternative adjusting means shown in Fig. 5 comprises a'strip 31 of material, such as flat spring steel, sharply corrugated as at 32 to receive and hold the teeth of the pawl. Obviously, the corrugations will be formed before the hardening or tempering of the strips so as to retain the corrugations when under tension. The free ends of these strips may be connected by a bar 27 for the purposes previously described.

While the device has been shown with duplicate springs andadjusting means, it will be understood that a greater or lesser number of springs and adjusting means may be used and also that the adjusting means may be eliminated entirely if desired, or the springs themselves continued farther around the sleeve and engaged dir ctly by the pawl. It will also be understood that numerous modifications may be made in the shape, number and construction of the lever and pawl without departing from the spirit of the invention, the precise combination of feature shown and described being merely for the purpose of illustration and therefore not to be regarded as limiting the invention to the precise combination or structural de tails of features.

The operation of the device is as follows The lever is drawn out, thus elongating the encircling means and permitting the sleeve to expand by its own resiliency, as shown in Fig. 1. The sleeve is then slipped over a piston which it is desired to insert in its cylinder and the lever swung in against the sleeve to the position shown in Fig. 2. This movement of the lever shortens the sleeve encircling means by twice the distance between the centers of the studs 25 and pin 18, so that the sleeve is contracted around the piston and compresses or contracts the piston rings to the diameter of the piston itself. During this contraction of the sleeve, there is a certain elongation. of the encircling means due to the yielding of the springs 24:. This yield is obviously necessary to avoid minute adjustments. The springs 2 1 are therefore necessarily strong enough to comprss the piston rings. Adjustments to lapt the device different sizes of pistons are made by pressing in on the tail 22 of the pawl, so as to disengage the teeth 21 thereof from the members 26 and permit sliding of these members under the pawl to increase or decrease the length of the sleeve encircling means. During the contraction or expans' of the sleeve, the lugs 1st slidably support the ends upon one another and hold them in ulinement and proper engagement. l i hen the sleeve is applied to a piston, care is taken to locate the lugs 16 at the bottom of the piston and to leave a small amount of the lower edge of the pistonprojecting beyond the sleeve. This projecting piston portion is now introduced into the engine cylinder and the piston and sleeve moved down until the lugs 16 rest on the end of the cylinder and stop further movement of the sleeve. The piston is now forced down out of the sleeve and into the cylinder. The sleeve makes a line contact with the end of the cylinder and therefore holds the piston rings in compression until they are fully into the cylinder, thus giving them no chance to expand and catch on the end of the cylinder. If the piston is being inserted in a solid head cylinder, such as is found in small two-cycle engines, the position of the sleeve on the piston is reversed and the piston is moved upwardly into the cylinder.

Fr. the foregoing, it will be readily seen that this invention provides for the quick and easy compression of all rings of a piston simultaneously and for the holding of these rings in compression until they are entirely in a cylinder, thereby avoiding much maneuvering and the expenditure of agreat deal of time, to say nothing of possible damage to the rings and possibly to the cylinder. When in closed position, the device extends very little beyond the piston at any point, so that it may be readily used in engines where the bore proper of the cylinder commences a considerable distance below the end of the casting and where very little clearance is allowed around the piston above the bore. proper.

Having thus described my invention, what I claim is 1. A band adapted to encircle a piston and the rings thereof, and contracting means encircling said band. 7

2. A device according to claim 1, in which the band contracting means is secured to the band adjacent one end of the band and remote from the opposite end.

3. A. member adapted to encircle a piston and its rings, said member overlapping at its ends, and means carried by one end of said member engaging the edges thereof adjacent the opposite end and holding the overlapping ends in alinement.

4. A member adapted to encircle a piston and its rings and a contracting device encircling said member and attached at its ends to the member.

5. A band adapted to encircle a piston. and its rings, a lever pivoted to said band, resilient means attached at one end to said lever and encircling the band and attached at its opposite end to the band.

6. A band adapted to encircle a piston and its rings, a resilient member encircling the band, and means for tensioning said member to contract the band.

7. A band adapted toencirclea piston and its rings, a lever pivoted to said band, a pawl carried by the band in proximity to said lever and a contracting element extending between the pawl and lever and encircling said band.

8. A band adapted to encircle a piston and its rings, releasable gripping means carried by the band, a flexible contracting element having one end adjustably engaged with said gripping means, and means carried by the band and connected to the opposite end of the flexible contracting element for exerting a pull thereon in a direction to contract the band.

In Witness whereof, I have hereunto set my hand.

ALBERT E. WATTS. 

